When I click an item with ingredients, the popup opens as usual, but I get an error in the console: “Uncaught TypeError: Cannot read property ‘ownerDocument’ of undefined”

I know this is a theme issue, as it doesn’t happen with Twenty Sixteen, but I was wondering if you’d run across this before and had any idea what might be causing it?

I have another site running the same theme, and that site does NOT return the same error.